Pregnancy Weight Gain Calculator
See how much weight gain is typical for you this week, based on your pre-pregnancy BMI and the US National Academies guidelines.
Track your weight against this range every week in Prego, in kg or lb, privately on your iPhone.
Recommended pregnancy weight gain
| Pre-pregnancy BMI | One baby | Twins |
|---|---|---|
| Under 18.5 | 28 to 40 lb (12.5 to 18 kg) | Ask your provider |
| 18.5 to 24.9 | 25 to 35 lb (11.5 to 16 kg) | 37 to 54 lb (17 to 25 kg) |
| 25 to 29.9 | 15 to 25 lb (7 to 11.5 kg) | 31 to 50 lb (14 to 23 kg) |
| 30 or more | 11 to 20 lb (5 to 9 kg) | 25 to 42 lb (11 to 19 kg) |
Most people gain only 1 to 4.5 lb (0.5 to 2 kg) in the first trimester, then gain at a steady weekly rate. The calculator uses that pattern to estimate a typical range for your current week. Read more in our guide to pregnancy weight gain.
Frequently asked questions
How much weight should I gain each week?
In the second and third trimesters, about 1 lb (0.4 to 0.5 kg) a week with a healthy pre-pregnancy BMI, less if your BMI was higher, and a little more if it was lower.
Is it bad to gain too much weight in pregnancy?
Gaining well above your range is linked to gestational diabetes, high blood pressure and a larger baby. But pregnancy isn't a time to diet; talk to your provider about healthy eating and activity.
Why do I use my pre-pregnancy weight?
The guidelines are based on your BMI before pregnancy, because that is what determines how much gain is healthy for you and your baby.
Estimates only. Your doctor or midwife may give you different dates or targets.